...we divided the patients with HNSCC who received cetuximab monotherapy (n = 36) into high PRSS3 expression (n = 20) and low PRSS1 expression groups (n = 16) based on the median PRSS3 level of the HNSCC tissue samples in the TCGA database. As expected, the patients with low PRSS3 expression had significantly longer PFS than the patients with high expression (median survival, 323 days versus 150 days, respectively; P = 0.0397; Fig. 6E).